The invention relates generally to methods and apparatus for the treatment of tumors using radiopharmaceuticals and, in particular, to a system for the computerized scheduling of the administration of such radiopharmaceuticals.
Radiopharmaceuticals include materials that may “target” specific tissues to deliver radioactive materials to those targeted tissues. Such radiopharmaceuticals generally combine a radioactive component such as a radionuclide with a tracer component exhibiting selective uptake in target tissue. Such radiopharmaceuticals allow imaging or treatment of specific tissues in the body after a generalized introduction of the radiopharmaceutical to the body, for example, by injection into the bloodstream.
When such radiopharmaceuticals are used for radiation therapy, the quantity and timing of the administration of the radiopharmaceutical must provide a radiation dose to the tissue sufficient to kill tumor cells and the radiation dose must be sustained for a time period related to the reproduction rate of tumor cells. While the selective uptake of radiopharmaceuticals may concentrate the radioactive component in the target tissue, the selectivity of such mechanisms is not perfect and accordingly the quantity and timing of the administration of the radiopharmaceuticals must also be limited to reduce toxicity to healthy-tissues that exhibit some uptake of the radiopharmaceutical.
Selecting the appropriate quantity and timing for administration of a radiopharmaceutical may be approximated by using a model of a “standard man” or extrapolation from animal models such as rodents to humans. Differences between animals and humans and even among humans make such determinations imprecise at best.